1. Technical Field
The present invention is related to a tension balancer which provides a continuous and appropriate tension to an overhead wire such as a train overhead wire, in particular an auxiliary hanging cable, a trolley line and a hanging overhead wire, and an auxiliary device when installing the tension balancer on an overhead wire.
2. Description of the Related Art
A continuous and appropriate tension is applied to a train overhead wire for supporting safe train transport and preventing slack or cable disconnection of the train overhead wire. Changes in the tension of a train overhead wire because of stretching or tilt of a support pillar due to a change in temperature can lead to accidents. Generally, a spring type tension balancer or a pulley type tension balancer is arranged on a train overhead wire in order to prevent such problems and in recent years the demand for spring type tension balancers is increasing due to their compact size and ease of use.
Among spring type tension balancers there is a coil spring type and gas spring type tension balancer. (Refer to Japanese Laid Open Patent 2008-114850 and Japanese Laid Open Patent 2000-255288).
Here, the installation of a tension balancer to a train overhead wire is explained. FIG. 12 is an overview diagram which shows a simplification of the process of installing a general tension balancer. When either of the tension balancers 100 are installed on a train overhead wire, as is shown in FIG. 12, a hollow rod 113 is pulled a certain size in advance using a wire grip 200, a yoke 201 and a wire 202 and a spring is installed in a compressed state. A shackle shaped connecting part 101 (also called a pull) is arranged on an end of the hollow rod 113 of the tension balancer 100 in order to install the tension balancer 100 on the train overhead wire, and a yoke through hole 102 into which the yoke 201 is inserted is arranged on the shackle shaped connecting part 101. The yoke 201 is inserted into the yoke through hole 102, a wire 202 is inserted into a wire grip wire insertion hole 203 arranged on the yoke 201, the wire 202 is wound up by the wire grip 200 and the hollow rod 113 is pulled. Then the tension balancer 100 is installed by latching the train overhead wire to the shackle shaped connecting part 101.
Installation of the tension balancer 100 to the train overhead wire is performed during a short period of time at night between the times when few trains pass. In addition, the burden on the installers is large because installation of the tension balancer is performed at a significant height, in particular winding up the wire 202 with the wire grip 200. Thus, if the hollow rod 113 is extracted a certain size in advance and fixed before leaving the factory, it is possible to reduce the burden on the installers and improve installation efficiency.
Thus, in Japanese Laid Open Patent 2004-42780, a fixing device 1 of a tension balancer is proposed. However, because this fixing device 1 is fixed to the tension balancer 100 by a semicircular contact component 2 and a suppression band 5 which suppresses the opposite side of the contact component 2 as is shown in FIG. 3 of Japanese Laid Open Patent 2004-42780, it is necessary to remove bolts of both ends of a fixing yoke 4 and bolts which fix a pair of anti-pressure levers 3 to an ear 2 (total of 4 bolts) in order to remove the fixing device 1 after installation of the tension balancer 100 (refer to Japanese Laid Open Patent 2004-42780) and thus installation efficiency is not improved. In addition, because this fixing device is developed with the assumption that it will be retrieved and reused, it is very expensive and it is necessary for a user to store the fixing device until the next retrieval. In particular, because the total length of a fixing device of a Shinkansen (bullet train) overhead wire is 500 mm or more, storage space becomes a problem.